Rail tracks, more commonly referred to as railway tracks or railroad tracks, are surface structures that support and guide trains or other transportation vehicles. Typically, a railroad track includes: (1) two rails on which wheels of a transportation vehicle travel, (2) a series of spaced sleepers (ties) disposed transversely to the rails, and (3) a ballast bed. The ballast bed may be formed, for example, of crushed stone and may serve multiple functions including providing support for the overlying structures and facilitating drainage. The ties may be formed, for example, of either timber, concrete or composite materials and may also provide support for the rails which are most commonly formed of steel. Located underneath the ballast bed is generally a sub grade formation which may be a natural ground surface and/or a geotechnical system installed to improve ground stability and drainage.
Despite modern technological developments, flat-bottom steel rails supported on timber or pre-stressed concrete ties, which are in turn laid on a crushed stone ballast bed, remain overwhelmingly the most common form of railroad track. Generally, the rails are attached to the ties via base plates (tie plates) which function to dissipate the load across a larger surface area. The rail may be fastened to the ties with resilient fastenings, or with cut spikes, as is common in North American practice.
A railroad crossing, also known as, for example, a railroad grade crossing, railroad at-grade crossing, grade crossing, or a level crossing refers to an “at-grade” intersection of a railway track by a road or path at one level, as opposed to a crossing by way of a bridge (above-grade) or a tunnel (below-grade).